A method for manufacturing a fin field-effect transistor (FinFET) device, comprises patterning a first layer on a substrate to form at least one fin, patterning a second layer under the first layer to remove a portion of the second layer on sides of the at least one fin, forming a sacrificial gate electrode on the at least one fin, and a spacer on the sacrificial gate electrode, selectively removing the sacrificial gate electrode, depositing an oxide layer on top and side portions of the at least one fin corresponding to a channel region of the at least one fin, performing thermal oxidation to condense the at least one fin in the channel region until a bottom portion of the at least one fin is undercut, and stripping a resultant oxide layer from the thermal oxidation, leaving a gap in the channel region between a bottom portion of the at least one fin and the second layer.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A fin field-effect transistor (FinFET) device, comprising: at least one fin formed on an oxide layer; a gap in a channel region of the at least one fin between a bottom portion of the at least one fin and the oxide layer, wherein the gap includes an undercut in the bottom portion of the at least one fin, and a recessed portion of the oxide layer; a gate structure around the at least one fin, including in the gap on an underside of the at least one fin; and a spacer layer formed on a side of the gap; wherein the gap includes a stepped portion between the undercut and the recessed portion; and wherein the stepped portion is formed in the spacer layer.
2. The fin field-effect transistor (FinFET) device of claim 1 , wherein the gate structure comprises a dielectric layer formed on the spacer layer and on the stepped portion.
3. The fin field-effect transistor (FinFET) device of claim 2 , wherein the gate structure further comprises a metal layer formed on the dielectric layer.
4. The fin field-effect transistor (FinFET) device of claim 2 , wherein the dielectric layer is further formed an underside of the bottom portion of the at least one fin.
5. The fin field-effect transistor (FinFET) device of claim 1 , wherein the gate structure comprises a dielectric layer formed around the at least one fin, and a metal layer formed on the dielectric layer.
6. A semiconductor device, comprising: at least one fin formed on an oxide layer, wherein the at least one fin comprises silicon germanium; a gap in a channel region of the at least one fin between a bottom portion of the at least one fin and the oxide layer, wherein the gap includes an undercut in the bottom portion of the at least one fin, and a recessed portion of the oxide layer; a gate structure around the at least one fin, including in the gap on an underside of the at least one fin; and a spacer layer formed on a side of the gap; wherein the gap includes a stepped portion between the undercut and the recessed portion; and wherein the stepped portion is formed in the spacer layer.
7. The semiconductor device of claim 6 , wherein the gate structure comprises a dielectric layer formed on the spacer layer and on the stepped portion.
8. The semiconductor device of claim 7 , wherein the gate structure further comprises a metal layer formed on the dielectric layer.
9. The semiconductor device of claim 7 , wherein the dielectric layer is further formed an underside of the bottom portion of the at least one fin.
10. The semiconductor device of claim 6 , wherein the gate structure comprises a dielectric layer formed around the at least one fin, and a metal layer formed on the dielectric layer.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
April 22, 2016
August 1, 2017
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